Unimog 404 Explained

Unimog 404
Type:Truck
Manufacturer:Daimler-Benz AG
Aka:404.1: Unimog U82
404.0: Unimog U110
Production:1955 – 1980
Assembly:Mercedes-Benz-Werk Gaggenau
Transmission:6-speed manual with 2 additional reverse gears
Predecessor:none
Successor:Unimog 435
Sp:uk

The Unimog 404, also called the Unimog S and Unimog 404 S, is a vehicle of the Unimog-series by Mercedes-Benz, produced in the Unimog plant in Gaggenau from 1955 to 1980. Marketed as Unimog U82, and later Unimog U110, 64,242 units of the two Unimog 404 types 404.0 and 404.1 were built, which makes the 404 the Unimog model with the highest production figure of all Unimogs. Unlike the Unimog 401, the 404 is rather a small 1.5-tonne-offroad-truck than an agricultural vehicle. In Germany, it was a common military vehicle and fire engine, 36,000 Unimog 404 were made for the Bundeswehr.

The first Unimog 404 concept-vehicle was made in 1953 and was slightly smaller than the series production model, it had a track width of 16000NaN0 and a wheelbase of 26700NaN0. Two prototypes for the French army followed in 1954, the first 1,100 series production models were also purchased by the French army. Since the French army did not want the spare wheel to occupy space for soldiers on the bed, the Daimler-Benz engineers decided to build the Unimog 404 with a downswept frame so the spare wheel could be mounted underneath the bed. This constructional feature also allowed more torsional flexing and, therefore, improved the offroad capabilities of the Unimog. Later, the downswept frame became a key constructional feature for the following Unimog types.[1]

At its introduction in 1955, the Unimog 404.1 was available as the 27000NaN0 wheelbase model with the Otto engine M 180 producing 600NaN0. In 1956, the 29000NaN0 wheelbase model of the 404.1 followed, available with the same engine. Both were sold as Unimog U82. The production of the U82 with the short wheelbase was stopped in 1971, while the long wheelbase model was built until 1980. Starting from 1971, the Unimog 404.0, sold as Unimog U110, was offered. It was fitted with the cab of the Unimog 406 and soon afterwards, with the model 404.012, it received the M 130 engine. However, only 1,791 404.0 were made. Also, 81 Unimog 404 were made with the diesel engine OM 615 (440NaN0) for the Portuguese market.

Technical description

The Unimog 404 is a small four-wheel offroad capable truck designed for a payload of 15000NaN0. Like other Unimogs, it has a ladder frame, two portal axles with reduction gears and coil springs with hydraulic shock absorbers for the rear and front axle. All four wheels and tyres have the same size and are fitted with hydraulic ATE drum brakes. The 404 is a rear-wheel-drive vehicle with switchable all-wheel-drive and additional differential locks.

A water-cooled straight-six Otto engine, type M 180 II-U, displacing 21950NaN0 powers the 404.1. It is fitted with a Zenith 32 NDIX offroad-carburettor and transmits the torque to a fully synchronised manual Daimler-Benz-six-speed-gearbox with two additional reverse gears. As clutch, the Fichtel & Sachs K 16 Z single-disc-dry-clutch is used.

The 404 was available both with a standard closed two-door-cab and as a two-door-cabriolet with a convertible top. The 404.1 has a divided windscreen, while the 404.0 with the cab of the Unimog model 406 has a single windscreen. Only the standard cab models have side windows in the doors. Special purpose vehicles, such as fire engines, were also made with an extended four-door-cab.

Overview of the 404-series

+ Types of the Unimog 404
Type number404-typeProduction periodCabWheelbase (mm)Engine power (kW)Engine typeNumber manufacturedNotes
404.010404.0Cabrio290081M 130113Cab of the Unimog 416, some units with M 180, 60 kW
404.011404.0Closed cab290081M 1301151Cab of the Unimog 406
404.012404.0Cabrio290081M 1307Cab of the 416
404.013404.0Closed cab290081M 130520Cab of the 406
404.111404.11955–1956Cabrio267063M 1801210Including 578 pre-series models, some units with 59 or 60 kW.
404.112404.1Cabrio and closed cab290060M 180185
404.113404.1Cabrio and closed cab290060M 1808106Some vehicles with 68 or 81 kW
404.114404.11956–1980Cabrio, chassis only and double cab290060M 18050321Some vehicles also with 68 kW
404.115404.1Closed cab290060M 1802548Some vehicles also with 68 kW
404.117404.11969–1970Cabrio290044OM 61581Model for the Portuguese market

Technical data

Type404.1404.0
Sold asU82 (short)U82 (long)U110
Years1955–19711956–19801971–1980
Mass (approx.)2900 kg2970 kg2970 kg
Length4600 mm4925 mm5025 mm
Width2130 mm2140 mm2130 mm
Height2190 mm2190 mm2250 mm
Wheelbase2700 mm2900 mm
Track width1630 mm
Ground clearance400 mm
Bed length2700 mm3000 mm
Bed width2000 mm
Bed height500 mm
Fuel tank capacity2 × 60 l
Tyres10–2010.5–20
Engine modelM 180/II UM 130
Engine typeStraight-six Otto, water-cooled
Fuel systemCarburettor type Zenith 32 NDIX
Displacement2195 cc2778 cc
Bore × stroke80 mm × 72.8 mm86.5 mm × 78.8 mm
Compression ratio7:1
Rated power (DIN 70020)NaNabbr=onNaNabbr=on at 4850 rpm110abbr=onNaNabbr=on at 4800 rpm
Max. torque (DIN 70020)16.11NaN1 at 3200 rpm
Top speed6th gear: 95 km/h1st gear: 7 km/h
2nd gear: 13 km/h
3rd gear: 24 km/h
4th gear: 44 km/h
5th gear: 72 km/h
6th gear: 95 km/h
1st reverse gear: 6 km/h
2nd reverse gear: 10 km/h
6th gear: 100 km/h
Climbing capability1st gear: 70%
2nd gear: 45%
3rd gear: 23%
4th gear: 11.5%
5th gear: 6.5%
6th gear: 3.5%
Source

Bibliography

Notes and References

  1. Carl-Heinz Vogler: ″UNIMOG 406 – Typengeschichte und Technik. Geramond. München. 2016. . Page 45. (In German)